Power sources for mobile devices like smartphones, tablet computers, and laptop computers include batteries that store charge in addition to conventional power cables. The availability of batteries that store charge enable these devices to be used as wireless devices that can operate as long as sufficient charge is available in the batteries to execute functions. A mobile device can perform multiple functions including, for example, telephony functions, computer software functions, Global Positioning System (GPS) functions, and the like. Each function that the mobile device performs causes a portion of the battery power to be consumed. As the number of functions that the mobile device performs and a frequency at which the device performs each function increases, the life of the device's battery decreases.